Pressure relief mechanism for an energy storage system

ABSTRACT

An energy storage system comprising at least one energy storage module implemented as a sealed or submersible unit and adapted to supply electrical energy to a hybrid vehicle. The energy storage module comprises an enclosure and at least one battery array located within the enclosure. The energy storage module includes a pressure relief panel held in place by springs that allows battery gases to escape if gas pressures reach a predetermined threshold. Pressure in the enclosure compresses the springs causing the pressure relief panel to temporarily move outward until pressure is relieved at which time the springs force the pressure relief panel to reseal the enclosure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US2011/63695, filed Dec. 7, 2011, which claims the benefit of U.S.Provisional Patent Application No. 61/420,389 filed Dec. 7, 2010, all ofwhich are hereby incorporated by reference in their entirety.

BACKGROUND

The present invention generally relates to an energy storage system and,more particularly, to an energy storage module to be incorporated into ahybrid electric motor vehicle to store high voltage energy.

Over the past few years, there has been a growing concern over globalclimate change due to an increase in carbon dioxide levels as well asoil supply shortages. As a result, some automobile manufactures andconsumers are beginning to have a greater interest in motor vehicleshaving low emissions and greater fuel efficiency. One viable option is ahybrid electric vehicle (HEV) which allows the vehicle to be driven byan electric motor, combustion engine, or a combination of the two.

Though various features are important to the overall HEV design, thesystem which stores the energy available for use by the vehicle is a keycomponent. The energy storage system is provided within the HEV to storethe energy created by a generator in order for that energy to beavailable for use by the hybrid system at some later time. For example,the stored energy may be used to drive an electric motor toindependently propel the motor vehicle or assist the combustion engine,thereby reducing gasoline consumption.

However, energy storage systems face a variety of design complications,such as over-heating, weight, complexity, ease of incorporation into thevehicle, ease of service, and cost, just to name a few. Additionally,known energy storage systems utilize only a specific and known number ofbattery packs or modules designed to meet a particular HEV designspecification. For example, a battery pack may be specifically designedto provide a specific amount of energy for a 300V vehicle. However, whena different amount of energy is required, such as a 600V system, adifferent battery pack must be designed to meet the needs of thatapplication. Known battery packs and storage systems can not be utilizedor otherwise implemented into different settings without a considerableamount of re-engineering and re-working.

Some known systems allow for separate battery packs to be electricallyconnected to a separate and distinct control box. Though the independentbattery packs may be added to or removed from the overall system, theseparate control box is still required. However, because available spacefor HEV components is at a premium, the inclusion of a separate anddistinct control box should be avoided. Additionally, in the event theseparate control box fails, the entire energy storage system is unableto function.

Thus, there is a need for improvement in this field.

SUMMARY

The energy storage system described herein addresses several of theissues mentioned above as well as others. For example, an energy storagesystem according to one embodiment of the present disclosure has aplurality of energy storage modules. The energy storage modules include,among other things, a plurality secondary battery arrays adapted tostore high voltage energy. An energy storage controller module iselectrically connected to various components within an energy storagemodule, such as, but not limited to, the battery arrays, a low voltageharness, a thermistor harness, and/or a vehicle signal connectorassembly, to name a few examples.

According to one aspect of the present disclosure, the energy storagemodules within the energy storage system are adapted to communicate withone another. In one embodiment, a pack-to-pack CAN bus is providedbetween each energy storage module. When multiple energy storage modulesare used to comprise the energy storage system, one energy storagemodule functions as a master energy storage module while the othersfunction as slave energy storage modules. The energy storage controllermodule within the master energy storage module is adapted to receiveinformation from the slave energy storage modules and communicate with atransmission/hybrid control module and the rest of the hybrid system asa single energy storage system.

According to another aspect of the disclosure, the energy storage systemcomprises at least one energy storage module adapted to supplyelectrical energy to a hybrid vehicle. The energy storage modulecomprises a primary enclosure, at least one battery array located withinthe primary enclosure, and an energy storage controller module locatedwithin the primary enclosure and electrically connected to the batteryarray. The energy storage controller module is further connected to ahybrid control module of the hybrid vehicle by a low voltage connector.A high voltage junction box is attached to a first end of the primaryenclosure and has a plurality of high voltage connection terminals. Thehigh voltage junction box has a first opening which corresponds to asecond opening of the primary enclosure such that the primary enclosureand high voltage junction box define a sealed cavity. At least one ofthe high voltage connection terminals is configured to receive a highvoltage conductor connected between the energy storage module and aninverter of the hybrid vehicle. A service disconnect is connected in acurrent path between the high voltage connection terminals and the atleast one battery array.

According to other aspects of the present disclosure, the energy storagesystem includes a thermal pad disposed between the battery arrays and aninterior surface of the primary enclosure. A heat sink is disposed on anexterior surface of the primary enclosure. The heat sink comprises aplurality of fins which may be disposed angularly outward in asymmetrical pattern with respect to a longitudinal axis of the primaryenclosure. A fan mounted to an exterior surface of a first end of theprimary enclosure is operable to direct air across the fins toward asecond end of the primary enclosure. The height or length of the finsmay be varied relative to the fan location to provide uniform coolingacross the battery cells in the battery array. An enclosing plate ismounted exterior to the heat sink and defining an airflow cavity,wherein the enclosing plate further directs air from the fan across theheat sink.

According to other aspects of the disclosure, the energy storage systemincludes a plug-in bussed electrical center, wherein at least a portionof the high voltage connections between the battery array and the bussedelectrical center are achieved using blade terminals. The primaryenclosure may further comprise a pressure relief panel disposed withinthe primary enclosure and operable to limit internal pressure within theprimary enclosure.

According to other aspects of the disclosure, the battery arraycomprises two parallel side rails and two parallel plates perpendicularto the side rails. The battery array may also include battery retainersbetween the battery cells. The battery retainers are formed from aninsulating material of sufficient thickness to limit thermal transferbetween the adjacent battery cells to a level which prevents venting ofa first battery cell from causing an adjacent second battery cell tovent. The battery array also includes a voltage sense board having aplurality of bus bars disposed therein. The bus bars connect a positiveterminal of a first battery cell to a negative terminal of a secondbattery cell. The voltage send board has missing final bus bars indesignated locations of the voltage sense board to limit the exposedvoltage to 50 volts during initial assembly. The final bus bars areinstalled last in conjunction with safety covers which have overlapportions to cover the installed final bus bars.

According to other aspects of the present disclosure, the controllermodule optionally includes a memory component. The memory component isadapted to record energy storage module usage and status history, suchas achieved power levels and duty cycles, to name a few examples.

Further forms, objects, features, aspects, benefits, advantages, andembodiments of the present invention will become apparent from adetailed description and drawings provided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a diagrammatic view of one example of a hybridsystem.

FIG. 2 illustrates a general diagram of an electrical communicationsystem in the FIG. 1 hybrid system.

FIG. 3 is a front perspective view of an energy storage module accordingto one embodiment of the present disclosure.

FIG. 4 is a rear perspective view of the energy storage module depictedin FIG. 3.

FIG. 5 is a bottom perspective view of the energy storage moduledepicted in FIG. 3.

FIG. 6 is an end view of the energy storage module depicted in FIG. 3.

FIG. 7A is an end view of an energy storage module with the access coverattached according to one embodiment of the present disclosure.

FIG. 7B is an end view of an energy storage module with the access coverremoved and the safety cover in place according to one embodiment of thepresent disclosure.

FIG. 8 is an end view of an energy storage module stacking arrangementaccording to one embodiment of the present disclosure.

FIG. 9 is a top view of an energy storage module with the top coverremoved according to one embodiment of the present disclosure.

FIG. 10 is a further perspective view the energy storage module of FIG.9 with the top cover removed according to one embodiment of the presentdisclosure.

FIG. 11 is a further perspective view of the energy storage moduledepicted in FIG. 10 with the top cover removed according to oneembodiment of the present disclosure.

FIG. 12 is a perspective view of a plenum end cap according to oneembodiment of the present disclosure.

FIG. 13 is a cross-sectional view of the end cap of FIG. 12 taken alongline A-A according to one embodiment of the present disclosure.

FIG. 14 is a bottom perspective view of an energy storage moduledepicting the cooling air flow according to one embodiment of thepresent disclosure.

FIG. 15 is an exploded view of a fan assembly according to oneembodiment of the present disclosure.

FIG. 16 is a perspective view of a bussed electrical center assemblyaccording to one embodiment of the present disclosure.

FIG. 17 is an exploded view of a battery array assembly according to oneembodiment of the present disclosure.

FIG. 18 is a perspective view of a battery cell.

FIG. 19 is an end, cross-sectional view of a battery array and plenumassembly according to one embodiment of the present disclosure.

FIG. 20 is a further end, cross-sectional view of a battery array andplenum assembly according to one embodiment of the present disclosure.

FIG. 21 is a perspective view of an energy storge controller moduleaccording to one embodiment of the present disclosure.

FIG. 22 is a perspective view of an energy storage module stackingarrangement according to one aspect of the present disclosure.

FIG. 23 is a perspective view of an energy storage module vehiclemounting arrangement according to one aspect of the present disclosure.

FIG. 24 is a front perspective view of an energy storage moduleaccording to one embodiment of the present disclosure.

FIG. 25 is a rear perspective view of the energy storage module depictedin FIG. 24.

FIG. 26 is a rear perspective view of an energy storage module stackingarrangement according to one embodiment of the present disclosure.

FIG. 27 is a lower rear perspective view of the energy storage moduledepicted in FIG. 24.

FIG. 28 is a lower front perspective view of a heat sink fin arrangementaccording to one embodiment of the present disclosure.

FIG. 29 is an upper rear perspective view of an energy store modulehaving a thermal pad according to one embodiment of the presentdisclosure.

FIG. 30 is a front perspective view of a high voltage junction box ofthe energy storage module of FIG. 24.

FIG. 31 is a front perspective view of the high voltage junction box ofFIG. 31 with the access cover removed.

FIG. 32 is a front perspective view of the high voltage junction box ofFIG. 31 with the inner safety cover removed.

FIG. 33A is a front perspective view of a plug-in bussed electricalcenter of the energy storage module of FIG. 24.

FIG. 33B is a rear perspective view of a plug-in bussed electricalcenter of the energy storage module of FIG. 24.

FIG. 34 is an exploded front perspective view of the energy storagemodule of FIG. 24.

FIG. 35 is a rear perspective view of the energy storage module of FIG.24 with the top cover and fan assembly removed.

FIG. 36 is an exploded rear perspective view of the energy storagemodule of FIG. 24.

FIG. 37 is a perspective view of a pressure relief panel of the energystorage module of FIG. 24 according to one embodiment.

FIG. 38 is an exploded perspective view of a battery array according toone embodiment of the present disclosure.

FIG. 39 is a perspective view of an assembled battery array according toone embodiment of the present disclosure.

FIG. 40 is front view of the battery array of FIG. 39 showing anindividual battery cell mounted in the battery array.

FIG. 41 is a top view of a voltage sense board assembly according to oneembodiment of the present disclosure.

FIG. 42 is a front view of the energy storage module of FIG. 24 mountedto a vehicular frame.

FIG. 43 is a perspective view of an isolator adapter for supporting anenergy storage module according to one embodiment.

FIG. 44 is a front view of a thermistor mounting arrangement accordingto one embodiment of the present disclosure.

FIG. 45 is a perspective view of the thermistor mounting arrangement ofFIG. 44.

FIG. 46A is a diagram showing a single energy storage module for use inan energy storage system according to one embodiment.

FIG. 46B is a diagram showing two energy storage modules connected inparallel according to one embodiment.

FIG. 46C is a diagram showing two energy storage modules connected inseries according to one embodiment.

FIG. 46D is a diagram showing two pairs of energy storage modulesconnected in a series/parallel arrangement according to one embodiment.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings, and specific language will be used to describe the same.It will nevertheless be understood that no limitation of the scope ofthe invention is thereby intended. Any alterations and furthermodifications in the described embodiments and any further applicationsof the principles of the invention as described herein are contemplatedas would normally occur to one skilled in the art to which the inventionrelates. One embodiment of the invention is shown in great detail,although it will be apparent to those skilled in the relevant art thatsome features not relevant to the present invention may not be shown forthe sake of clarity.

The reference numerals in the following description have been organizedto aid the reader in quickly identifying the drawings where variouscomponents are first shown. In particularthe drawing in which an elementfirst appears is typically indicated by the left-most digit(s) in thecorresponding reference number. For example, an element identified by a“100” series reference numeral will first appear in FIG. 1, an elementidentified by a “200” series reference numeral will first appear in FIG.2, and so on. With reference to the Specification, Abstract, and Claimssections herein, it should be noted that the singular forms “a”, “an”,“the”, and the like include plural referents unless expressly discussedotherwise. As an illustration, references to “a device” or “the device”include one or more of such devices and equivalents thereof.

FIG. 1 shows a diagrammatic view of a hybrid system 100 according to oneembodiment. The hybrid system 100 illustrated in FIG. 1 is adapted foruse in commercial-grade trucks as well as other types of vehicles ortransportation systems, but it is envisioned that various aspects of thehybrid system 100 can be incorporated into other environments. As shown,the hybrid system 100 includes an engine 102, a hybrid module 104, anautomatic transmission 106, and a drive train 108 for transferring powerfrom the transmission 106 to wheels 110. The hybrid module 104incorporates an electrical machine, commonly referred to as an eMachine112, and a clutch 114 that operatively connects and disconnects theengine 102 from the eMachine 112 and the transmission 106.

The hybrid module 104 is designed to operate as a self-sufficient unit,that is, it is generally able to operate independently of the engine 102and transmission 106. In particular, its hydraulics, cooling andlubrication do not directly rely upon the engine 102 and thetransmission 106. The hybrid module 104 includes a sump 116 that storesand supplies fluids, such as oil, lubricants, or other fluids, to thehybrid module 104 for hydraulics, lubrication, and cooling purposes.While the terms oil or lubricant will be used interchangeably herein,these terms are used in a broader sense to include various types oflubricants, such as natural or synthetic oils, as well as lubricantshaving different properties. To circulate the fluid, the hybrid module104 includes a mechanical pump 118 and an electrical (or electric) pump120. With this combination of both the mechanical pump 118 andelectrical pump 120, the overall size and, moreover, the overall expensefor the pumps is reduced. The electrical pump 120 can supplementmechanical pump 118 to provide extra pumping capacity when required. Inaddition, it is contemplated that the flow through the electrical pump120 can be used to detect low fluid conditions for the hybrid module104. In one example, the electrical pump 120 is manufactured by MagnaInternational Inc. of Aurora, Ontario, Canada (part number 29550817),but it is contemplated that other types of pumps can be used.

The hybrid system 100 further includes a cooling system 122 that is usedto cool the fluid supplied to the hybrid module 104 as well as thewater-ethylene-glycol (WEG) to various other components of the hybridsystem 100 which will be described later in further detail. In onevariation, the WEG can also be circulated through an outer jacket of theeMachine 112 in order to cool the eMachine 112. It should be noted thatthe hybrid system 100 will be described with respect to a WEG coolant,but other types of antifreezes and cooling fluids, such as water,alcohol solutions, etc., can be used. Looking at FIG. 1, the coolingsystem 122 includes a fluid radiator 124 that cools the fluid for thehybrid module 104. The cooling system 122 further includes a mainradiator 126 that is configured to cool the antifreeze for various othercomponents in the hybrid system 100. Usually, the main radiator 126 isthe engine radiator in most vehicles, but the main radiator 126 does notneed to be the engine radiator. A cooling fan 128 flows air through bothfluid radiator 124 and main radiator 126. A circulating or coolant pump130 circulates the antifreeze to the main radiator 126. It should berecognized that other various components besides the ones illustratedcan be cooled using the cooling system 122. For instance, thetransmission 106 and/or the engine 102 can be cooled as well via thecooling system 122.

The eMachine 112 in the hybrid module 104, depending on the operationalmode, at times acts as a generator and at other times as a motor. Whenacting as a motor, the eMachine 112 draws alternating current (AC). Whenacting as a generator, the eMachine 112 creates AC. An inverter 132converts the AC from the eMachine 112 and supplies it to an energystorage system 134. The eMachine 112 in one example is an HVH410 serieselectric motor manufactured by Remy International, Inc. of Pendleton,Ind., but it is envisioned that other types of eMachines can be used. Inthe illustrated example, the energy storage system 134 stores the energyand resupplies it as direct current (DC). When the eMachine 112 in thehybrid module 104 acts as a motor, the inverter 132 converts the DCpower to AC, which in turn is supplied to the eMachine 112. The energystorage system 134 in the illustrated example includes three energystorage modules 136 that are daisy-chained together to supply highvoltage power to the inverter 132. The energy storage modules 136 are,in essence, electrochemical batteries for storing the energy generatedby the eMachine 112 and rapidly supplying the energy back to theeMachine 112. The energy storage modules 136, the inverter 132, and theeMachine 112 are operatively coupled together through high voltagewiring as is depicted by the line illustrated in FIG. 1. While theillustrated example shows the energy storage system 134 including threeenergy storage modules 136, it should be recognized that the energystorage system 134 can include more or less energy storage modules 136than is shown. Moreover, it is envisioned that the energy storage system134 can include any system for storing potential energy, such as throughchemical means, pneumatic accumulators, hydraulic accumulators, springs,thermal storage systems, flywheels, gravitational devices, andcapacitors, to name just a few examples.

High voltage wiring connects the energy storage system 134 to a highvoltage tap 138. The high voltage tap 138 supplies high voltage tovarious components attached to the vehicle. A DC-DC converter system140, which includes one or more DC-DC converter modules 142, convertsthe high voltage power supplied by the energy storage system 134 to alower voltage, which in turn is supplied to various systems andaccessories 144 that require lower voltages. As illustrated in FIG. 1,low voltage wiring connects the DC-DC converter modules 142 to the lowvoltage systems and accessories 144.

The hybrid system 100 incorporates a number of control systems forcontrolling the operations of the various components. For example, theengine 102 has an engine control module 146 that controls variousoperational characteristics of the engine 102 such as fuel injection andthe like. A transmission/hybrid control module (TCM/HCM) 148 substitutesfor a traditional transmission control module and is designed to controlboth the operation of the transmission 106 as well as the hybrid module104. The transmission/hybrid control module 148 and the engine controlmodule 146 along with the inverter 132, energy storage system 134, andDC-DC converter system 140 communicate along a communication link as isdepicted in FIG. 1.

To control and monitor the operation of the hybrid system 100, thehybrid system 100 includes an interface 150. The interface 150 includesa shift selector 152 for selecting whether the vehicle is in drive,neutral, reverse, etc., and an instrument panel 154 that includesvarious indicators 156 of the operational status of the hybrid system100, such as check transmission, brake pressure, and air pressureindicators, to name just a few.

As noted before, the hybrid system 100 is configured to be readilyretrofitted to existing vehicle designs with minimal impact to theoverall design. All of the systems including, but not limited to,mechanical, electrical, cooling, controls, and hydraulic systems, of thehybrid system 100 have been configured to be a generally self-containedunit such that the remaining components of the vehicle do not needsignificant modifications. The more components that need to be modified,the more vehicle design effort and testing is required, which in turnreduces the chance of vehicle manufacturers adopting newer hybriddesigns over less efficient, preexisting vehicle designs. In otherwords, significant modifications to the layout of a preexisting vehicledesign for a hybrid retrofit requires, then, vehicle and product linemodifications and expensive testing to ensure the proper operation andsafety of the vehicle, and this expenses tends to lessen or slowadoption of hybrid systems. As will be recognized, the hybrid system 100not only incorporates a mechanical architecture that minimally impactsthe mechanical systems of pre-existing vehicle designs, but the hybridsystem 100 also incorporates a control/electrical architecture thatminimally impacts the control and electrical systems of pre-existingvehicle designs.

FIG. 2 shows a diagram of one example of a communication system 200 thatcan be used in the hybrid system 100. While one example is shown, itshould be recognized that the communication system 200 in otherembodiments can be configured differently than is shown. Thecommunication system 200 is configured to minimally impact the controland electrical systems of the vehicle. To facilitate retrofitting toexisting vehicle designs, the communication system 200 includes a hybriddata link 202 through which most of the various components of the hybridsystem 100 communicate. In particular, the hybrid data link 202facilitates communication between the transmission/hybrid control module148 and the shift selector 152, inverter 132, the energy storage system134, the low voltage systems/accessories 144, and the DC-DC convertermodules 142. Within the energy storage system 134, an energy storagemodule data link 204 facilitates communication between the variousenergy storage modules 136. However, it is contemplated that in otherembodiments the various energy storage system modules 136 cancommunicate with one another over the hybrid data link 202. With thehybrid data link 202 and the energy storage module data link 204 beingseparate from the data links used in the rest of the vehicle, thecontrol/electrical component of the hybrid system 100 can be readilytied into the vehicle with minimum impact. In the illustrated example,the hybrid data link 202 and the energy storage module data link 204each have a 500 kilobit/second (kbps) transmission rate, but it isenvisioned that data can be transferred at other rates in otherexamples. Other components of the vehicle communicate with thetransmission/hybrid control module 148 via a vehicle data link 206. Inparticular, the shift selector 152, the engine control module 146, theinstrument panel 154, an antilock braking system 208, a body controller210, the low voltage systems/accessories 144, and service tools 212 areconnected to the vehicle data link 206. For instance, the vehicle datalink 206 can be a 250 k J1939-type data link, a 500 k J1939-type datalink, a General Motors LAN, or a PT-CAN type data link, just to name afew examples. All of these types of data links can take any number offorms such as metallic wiring, optical fibers, radio frequency, and/or acombination thereof, just to name a few examples.

In terms of general functionality, the transmission/hybrid controlmodule 148 receives power limits, capacity available current, voltage,temperature, state of charge, status, and fan speed information from theenergy storage system 134 and the various energy storage modules 136within. The transmission/hybrid control module 148 in turn sendscommands for connecting the various energy storage modules 136 so as tosupply voltage to and from the inverter 132. The transmission/hybridcontrol module 148 also receives information about the operation of theelectrical pump 120 as well as issues commands to the auxiliaryelectrical pump 120. From the inverter 132, the transmission/hybridcontrol module 148 receives a number of inputs such as themotor/generator torque that is available, the torque limits, theinverter's voltage current and actual torque speed. Based on thatinformation, the transmission/hybrid control module 148 controls thetorque speed and the pump 130 of the cooling system. From the inverter132, it also receives a high voltage bus power and consumptioninformation. The transmission/hybrid control module 148 also monitorsthe input voltage and current as well as the output voltage and currentalong with the operating status of the individual DC-DC convertermodules 142 of the DC-DC converter system 140. The transmission/hybridcontrol module 148 also communicates with and receives information fromthe engine control module 146 and in response controls the torque andspeed of the engine 102 via the engine control module 146.

Turning to FIG. 3, certain embodiments of the energy storage module 136will now be discussed. As depicted, energy storage module 136 comprisesa primary enclosure 301 having a lower housing 302 and an upper cover304. The lower housing 302 and upper cover 304 are constructed andarranged to withstand large vibrations and high shock loads. In order toprovide heavy duty strength for operation in certain environments (i.e.,heavy duty trucking) while also being mindful of weight, lower housing302 and upper cover 304 are constructed of aluminum in one embodiment,though other materials, such as steel, may also be used. According toone embodiment, the energy storage module 136 is constructed towithstand 100G shock loads and 25G vibration loads.

A plurality of mounting feet 306 are located on the bottom of lowerhousing 302 to assist in the mounting of the energy storage module 136to the HEV body or frame. Additionally, a plurality of indentations 316are provided around the periphery of lower housing 302 to also assist inthe optional stacking of multiple energy storage modules.

Located at one end 307 of the energy storage module 136 is a highvoltage junction box 308. As will be described in more detail below, aseries of high voltage cables 310 are connected to the high voltagejunction box 308 to deliver high voltage power to and from energystorage module 136. The high voltage junction box 308 may be formedintegral to the primary enclosure 301 or as a separate unit.

Also provided on the end 307 of the energy storage module 136 are aservice disconnect 312 and a low-voltage vehicle signal connector 314.The service disconnect 312 is provided to break the current path betweenthe high voltage energy sources within the primary enclosure 301 and theelectronics within the high voltage junction box 308. The servicedisconnect 312 ensures user safety during service operations of theenergy storage module 136. The vehicle signal connector 314 allows forthe energy storage module 136 to be in electrical and communicativeconnection with other components of the hybrid system, such as, but notlimited to, the transmission/hybrid control module 148. In oneembodiment, the vehicle signal connector 314 is a forty seven (47) wayconnector which includes gold terminals. According to one aspect of thepresent disclosure, the vehicle signal connector 314 is also designedand validated for heavy duty applications. Though the embodimentillustrated in FIG. 3 includes a single vehicle signal connector 314,other embodiments may include two or more signal connectors.

FIG. 4 depicts a perspective view of the other end 315 of the energystorage module 136. As shown, a plenum inlet cover 402 and a plenumoutlet cover 404 are provided at the same end 315 of the energy storagemodule 136. The covers 402, 404 are constructed and arranged to guidethe air entering and exiting the energy storage module 136. In someembodiments, covers 402, 404 may be connected and have a unitary design.An exhaust vent 406 is provided to allow for the safe exhaustion ofpotentially harmful gases and fumes in the event of a failure of abattery cell, as will be discussed in greater detail below. A pluralityof recesses 408 is provided on the upper cover 304 to assist in theoptional stacking and mating of multiple energy storage modules.

In some embodiments, the energy storage module 136 has a physicaldimension of 1100 mm×470 mm×235 mm, though larger and smaller dimensionsmay be warranted depending upon a particular HEV design and are withinthe scope of the present disclosure. In some embodiments, the energystorage module has a weight between 50 and 100 kilograms, though lighterand heavier weights are within the scope of the present disclosure.

FIG. 5 provides a perspective view of the underside of the lower housing302 of energy storage module 136. As depicted, lower housing 302includes a plurality of protrusions 502 on its bottom surface. In theillustrated embodiment, recesses 408 correspond to the configuration ofthe protrusions 502 in order to provide a stable arrangement when anadditional energy storage module is stacked on top of the upper cover304.

FIG. 6 provides a more detailed view of the end 307 of the energystorage module 136 including the high voltage junction box 308. In theillustrated embodiment, all electrical connections are made available onthe same end 307 of the energy storage module 136. The high voltagejunction box 308 includes two auxiliary direct current (DC) connections602 and corresponding auxiliary fuses 604. These components provideadditional sources of high voltage DC power to be used by the hybridsystem and/or vehicle accessories. In one embodiment, one DC connection602 allows the energy storage module 136 to be connected to the DC-DCconverter system 140. The high voltage junction box 308 also includes ahigh voltage interlock (HVIL) 606 which safely isolates the high voltagecomponents from the rest of the vehicle when triggered.

As noted above, a series of high voltage cables 310 connect a series ofperipheral components to the high voltage junction box 308 via highvoltage connectors 616. More specifically, a positive inverter cable 608provides the positive connection to inverter 132, whereas a negativeinverter cable 610 provides the negative connection to inverter 132. Apositive mating cable 612 provides the positive connection to anadditional, stacked energy storage module or other high voltage deviceand a negative mating cable 614 provides the negative connection to anadditional, stacked energy storage module or other high voltage device.Positive cables 608, 612 are electrically connected to positive terminal618 and negative cables 610, 614 are electrically connected to negativeterminal 620.

In one embodiment, the ends of cables 310 and connectors 616 are keyedin order to prevent connection error. In one arrangement, each cable isprovided with an individual key. In another embodiment, the positivecables 608, 612 are keyed the same, while the negative cables 610, 614are keyed the same but different from positive cables 608, 612.

FIGS. 7A, 7B depict the high voltage junction box 308 safety accessfeatures according to one embodiment of the present disclosure. As shownin FIG. 7A, the high voltage junction box 308 is a sealed unit protectedby an access cover 702. In order to gain access to inside the junctionbox 308, fasteners 704 must be removed and the access cover 702 may belifted away.

FIG. 7B depicts the high voltage junction box 308 with the access cover702 removed. For precautionary purposes, a safety cover 706 is providedto act as a further barrier to the high voltage terminals behind it. Inorder to access the electronics depicted in FIG. 5, an HVIL resistor 708must be removed in order to disconnect the HV power to the positiveterminal 618 and the negative terminal 620. Additionally, the fasteners710 must be taken out before the safety cover 706 can be removed. Oncethose actions are completed, the electronics within the high voltagejunction box 308 as illustrated in FIG. 5 can then be safely accessed.

FIG. 8 illustrates the HV power connections between stacked energystorage modules. As shown, one energy storage module 802 functions asthe master module. Master module 802 is connected to the hybrid systeminverter 132 via cables 608, 610. A second energy storage module 804functions as a slave module. In the illustrated embodiment, slave module804 is not connected to the inverter 132 but is only connected to themaster module 802 via cables 612, 614. Therefore, master module 802essentially contains two sets of main power connections: one to thehybrid system, one to the slave module 804.

FIG. 9 depicts a top view of the energy storage module 136 in which theupper cover 304 has been removed in order to show various components. Inthe illustrated embodiment, energy storage module 136 includes a firstbattery array 902 and a second battery array 904. The battery arrays902, 904 allow for both (a) the high voltage energy received from theinverter 132 to be stored and (b) to provide high voltage energy to theinverter 132 in order to power an appropriate hybrid system component,as well as other system components via auxiliary DC connections 602.Each battery array 902, 904 is connected to a high voltage harness 906which is electrically connected to a controller module 908. The batteryarrays 902, 904 are also electrically connected to a bussed electricalcenter (BEC) 918, which is constructed and arranged to, among otherthings, properly distribute the high voltage energy to the high voltagejunction box 308 and cables 310.

In addition to the high voltage harness 906, the controller module 908is also electrically connected to a low voltage harness 910. The lowvoltage harness 910 provides a communicative connection between thecontroller 908 and various components within the energy storage module136, such as, but not limited to, fan assembly 912, vehicle signalconnector assembly 914, and BEC 918. A high voltage interlock switch 916is also provided inside the energy storage module 136 as a furthersafety precaution. The high voltage interlock switch 916 is inelectrical and communicative connection with BEC 918. BEC 918 is adaptedto trigger switch 916 and disconnect the high voltage power from thehigh voltage junction box 308 if the high voltage electrical conditionsbecome unsafe.

In other, non-illustrated embodiments, the various components may berearranged and relocated, such as, but not limited to, BEC 918 andportions of fan assembly 912. In one embodiment, the fan assembly 912may be positioned outside of primary enclosure 301. In otherembodiments, BEC 918 may be located inside high voltage junction box308. As appreciated by those of ordinary skill in the art, thesemodifications and others may be implemented to reduce high voltageexposure under service conditions.

FIGS. 10 and 11 provide a more detailed overview of the componentswithin the energy storage module 136. As illustrated, the high voltagejunction box 308 includes both a positive header assembly 1002 andnegative header assembly 1004. Disposed underneath the access cover 702is access cover seal 1006 which ensures that particles and moisture arekept out of the high voltage junction box 308. Also provided is highvoltage interlock conductor 1008. In certain embodiments, the back ofthe high voltage junction box 308 may be open with respect to the lowerhousing 302 to allow the various electrical connections between the highvoltage junction box 308 and the BEC 918 or controller 908. In otherembodiments, the back of the high voltage junction box may be sealedwith respect to the lower housing 302, with the wiring connectionsbetween the high voltage junction box 308 and the BEC 918 beingindividually sealed to prevent contaminants from entering the primaryenclosure 301 via the high voltage junction box 308.

The service disconnect 312 comprises service disconnect plug 1010 andbase 1012. The service disconnect plug 1010 of service disconnect 312 isprovided to break the current path between the high voltage energysources within the energy storage module 136 and the electronics withinthe high voltage junction box 308.

A seal 1014 is disposed underneath the upper cover 304 to ensure thatparticles and moisture are kept out of the energy storage module 136. Aseries of bolts 1016 are utilized to fix the upper cover 304 to thelower housing 302, though other known techniques may be utilized. Aroundthe outer periphery of both the upper cover 304 and the lower housing302 are a plurality of holes 1024 adapted to facility both the liftingof the energy storage module 136 as well as the stacking of multipleenergy storage modules 136.

A safety cover 1018 is positioned on top of the battery array 902. Thesafety cover 1018 protects the battery cells comprising the batteryarray 902 from damage and contact with the other components within theenergy storage module 136. A battery end plate seal 1032 is provided ateach end of the battery arrays 902, 904 to further protect the arraysfrom contamination and damage.

Positioned between the plenum inlet cover 402 and the fan assembly 912is a plenum/fan interface 1020. An inlet air sensor 1022 is locateddownstream of the plenum/fan interface 1020 and is adapted to monitorthe air flow into the energy storage module 136. A fan housing seal 1030is also provided adjacent to the fan assembly 912.

As discussed with respect to FIG. 9, the controller module 908 iselectrically and communicatively connected to low voltage harness 910,as well as a thermistor high harness 1026 and a thermistor low harness1028. As appreciated by those of skill in the art, a thermistor is aresistor whose resistance varies with changes in temperature.Accordingly, the thermistor harnesses 1026, 1028 may communicatetemperature data related to the BEC 918, inlet air, outlet air, thebattery arrays 902, 904, the fan assembly 912, etc.

Looking now at FIG. 11, BEC 918 includes a positive high voltageconductor 1102 electrically connected to the positive header assembly1002 and a negative high voltage conductor 1104 electrically connectedto the negative header assembly 1004. BEC 918 further includes anegative conductor 1106.

A high voltage interlock header pass through 1108 is provided adjacentto high voltage junction box 308. Referring now also to FIGS. 9 and 10,the HVIL pass through 1108 electrically connects the HVIL conductor 1008with the HVIL switch 916. Accordingly, when the HVIL resistor 708 isremoved from the HVIL 606, the HVIL pass through 1108 indicates an opencircuit and the HVIL switch 916 is tripped to disconnect the highvoltage power from the electronics within the high voltage junction box308.

During operation, various components within energy storage module 136generate a considerable amount of heat, particularly the battery arrays902, 904. In order for the components to properly function, the heatmust be adequately dissipated. Pursuant to the illustrated embodiment,the battery arrays 902, 904 and other components within the energystorage module 136 are air cooled. In order to guide and provide aseparate air flow along the battery arrays 902, 904, a plenum cover 1110is provided between the battery arrays 902, 904. The plenum cover 1110has a fan end 1112, which is positioned adjacent to the fan assembly912, and a BEC end 1114, which is located near the BEC 918. In theillustrated embodiment, the fan end 1112 is taller than the BEC end1114. The tapering of plenum cover 1110 ensures that the air flowthrough the plenum maintains an adequate velocity as it flows away fromthe fan assembly 912. A plenum air seal 1116 is disposed beneath theplenum cover 1110.

A mid pack conductor 1118 electrically connects the first battery array902 with the second battery array 904. The mid pack conductor 1118allows the controller module 908 to monitor the battery arrays 902, 904as if they were a single array.

As previously discussed, the plenum inlet cover 402 and the plenumoutlet cover 404 are provided at one end 315 of the primary enclosure301. In order to ensure no debris or moisture is introduced into theenergy storage module 136, an inlet cover seal 1120 is provided betweenthe outer periphery of the plenum inlet cover 402 and the lower housing302. Similarly, an outlet cover seal 1122 is provided between the outerperiphery of the plenum outlet cover 404 and the lower housing 302.

In one embodiment, potentially harmful and noxious gases which may ventwhen under abuse or failure from the battery cells within the batteryarrays 902, 904, exhaust vent manifold 1124 is provided along the lengthof the battery arrays 902, 904. The vent tubes comprising manifold 1124are connected at a vent tee 1126, with the exhaust gases then beingdelivered to the exhaust vent 406. Known techniques can then beimplemented to treat or otherwise dispose of the exhaust gases.

FIG. 12 provides a perspective view of a plenum end cap 1200. The plenumend cap 1200 may be used as plenum inlet cover 402 and/or plenum outletcover 404. The end cap 1200 comprises a body 1202 and a plurality ofmounting flanges 1204. The mounting flanges 1204 are constructed andarranged to lay flat against and provide a surface to be affixed to thelower housing 302. In the illustrated embodiment, the end cap 1200 isaffixed to the lower housing 302 by a plurality of fasteners placedthrough the holes 1206. In other embodiments, the end cap 1200 may beheld to the lower housing 302 through other known techniques, such as,but not limited to, nails, welding, glue, etc. A filter 1208 is providedto limit the amount of debris that enters the air plenum.

FIG. 13 is a cross-sectional view of end cap 1200 taken along line 13-13of FIG. 12. As illustrated, the bottom end of the cap body 1202 is opento provide an external air flow opening 1302, which assists in limitingthe amount of debris entering the air plenum. However, in order tofurther ensure that debris does not enter the air plenum, a particlescreen 1304 is optionally provided within the opening 1302. Within endcap 1200 is an air deflector 1306. The area within the mounting flanges1204 defines an air inlet opening 1308, which is optionally filled withthe filter 1208. The air inlet opening 1308 is positioned adjacent tothe plenum/fan interface 1020. In one embodiment, the air inlet opening1308 has a dimension of 100 mm×75 mm, though other dimensions may beappropriate depending on design specifications.

According to one embodiment of the present disclosure, a heating and/orcooling unit is positioned adjacent to plenum/fan interface 1020. Insuch an embodiment, the controller module 908 works in conjunction withthe thermistor harnesses 1026, 1028 to determine if the introduction ofhot or cold air into the energy storage system is warranted. In yetother embodiments, the inlet cover 402 and the outlet cover 404 are influid connection, which allows the air to be re-circulated throughoutthe energy storage module 136 in cold weather conditions. In furtherembodiments, the plenum inlet cover 402 and plenum outlet cover 404 areconnected to a snorkel-type device. The snorkel device provides a meansto keep the energy storage module 136 free of water in the event itbecomes submerged. The snorkel device may also be used to transport coolair to the plenum inlet cover 402 of the energy storage module 136.

FIG. 14 generally depicts the cooling air flow through the energystorage module 136. As previously discussed, the plenum inlet cover 402and the plenum outlet cover 404 are provided on the same end 315 of theenergy storage module 136. When fan assembly 912 is powered on, externalair is drawn into the energy storage module 136, as indicated by arrow1402. The air is forced along the battery array 902, around the BEC 918,and back up along the battery array 904. The exhaust air is generallyindicated by arrow 1404. The cooling air flow is guided along by theplenum cover 1110 in a U-shape pattern as indicated by arrow 1403. Asappreciated by those of skill in the art, the battery arrays 902, 904generate a considerable amount of heat during operation. If the heat isnot dissipated, the arrays may overheat and malfunction. Accordingly,the air flow provided by the present disclosure adequately dissipatesthat heat.

FIG. 15 is an exploded view of the fan assembly 912 according to oneembodiment. As illustrated, the fan assembly 912 comprises a first fanhousing 1502, inlet air sensor 1022, second fan housing 1504 andbrushless fan 1506. The first fan housing 1502 is positioned adjacent tothe plenum/fan interface 1020 and mounted directly to the lower housing302. The inlet air sensor 1022 is constructed and arranged to monitorthe inlet air flow coming into the cooling plenum. The information iscommunicated to the controller module 908.

The first fan housing 1502 is constructed and arranged to receive thesecond fan housing 1504. The fan 1506 is mounted to the second fanhousing 1504 by a plurality of screws 1508. The fan 1506 includes acommunication connector 1510 which allows the controller module 908 tomonitor and control the operation of the fan 1506. In one embodiment,the fan 1506 is brushless and operates at 12V, although other types offans and voltage levels may be used.

FIG. 16 provides a more detailed view of the BEC 918. According to theillustrated embodiment, the BEC 918 is a single serviceable unit whichcan be replaced as a whole. The BEC 918 comprises a positive contact1602, a negative contact 1604, and a pre-charge contactor 1606. Thecontacts 1602, 1604, 1606 connect the battery arrays 902, 904 to theappropriate electrical connections within the high voltage junction box308. Accordingly, the contacts 1602, 1604, 1606 work in conjunction withthe HVIL 606 to disconnect the high voltage from the rest of thevehicle. A pre-charge resistor 1608 is provided to slowly charge theinverter 132 when energy is delivered from the energy storage module 136during vehicle start-up. A Y-cap 1610 is provided to reduce highfrequency noise from the DC wires. A current sensor 1612 monitors theamount of high voltage current flowing in or out of the energy storagemodule 136. That information is optionally provided to the controllermodule 908. If the current exceeds a certain threshold, the high voltageinterlock 606 is triggered and the high voltage power is disconnectedfrom the electronics within the high voltage junction box 308. In oneembodiment, current sensor 1612 is a dual range sensor.

FIG. 17 is an exploded view of a battery array 1700. The battery array1700 comprises a plurality of battery cells 1702 separated from oneanother by a cell retainer 1704. The battery cells 1702 are secondarybatteries capable of being repeatedly charged and discharged, such as,but not limited to, nicad (Ni—Cd), nickel-hydride, and/or lithium-iontypes. Battery cells manufactured by Samsung, Sanyo and GS YuasaCorporation have been found to be acceptable depending upon design andsize considerations.

At each end of the battery array 1700 is an end plate 1706, which worksin conjunction with two side rails 1708 to hold the battery cells 1702and the cell retainers 1704 in place. Once the battery cells 1702, cellretainers 1704, end plates 1706, and side rails 1708 are properlyaligned, the structure is held together by a series of screws 1710,though other known means may be used. In one embodiment, the batteryarray 1700 is made up of forty six individual battery cells 1702.

A series of seals 1712 is sandwiched between vent manifold sections1714. The ends of the vent manifold sections 1714 are constructed andarranged to connect with the exhaust vent manifold 1124. Above the ventmanifold assemblies 1714 are positioned a voltage sense board 1716,followed then by a safety cover 1720. The voltage sense board 1716includes a harness connection 1718 which is constructed and arranged toconnect with the high voltage harness 906.

FIG. 18 is a perspective view of an individual battery cell 1702. Thebattery cell 1702 includes two terminals 1802 and a vent 1804. Theterminals 1802 provide a contact point upon which high voltage energycan be passed in order to be stored within the cell 1702. The terminals1802 also provide a contact point upon which high voltage energy can beextracted from the battery cell 1702 in order to provide power to thehybrid vehicle system. The vent 1804 provides a specific location inwhich exhaust gases may be expelled in the event the battery cell 1702is abused, overheats, or malfunctions.

FIGS. 19 and 20 illustrate an end view of the battery array 1700 wheninstalled within the energy storage module. Buss bars 1902 provide anelectrical connection between the voltage sense board 1716 and the cellterminals 1802. Additionally, it is noted that cell vent 1804 ispositioned directly beneath the vent manifold section 1714, which is inturn connected to the vent manifold 1124. Such an arrangement ensuresthat any harmful or noxious gases expelled from the battery cell 1702are properly exhausted from the energy storage module 136.

FIG. 21 is a perspective view of the controller module 908. Disposedalong one edge of the controller module 908 is a plurality of highvoltage connections 2102. As discussed hereinabove, the high voltageconnections 2102 are principally used to receive the high voltageharness 906 which is connected to the battery arrays 902, 904. Throughthe high voltage harness 906, the controller module 908 can individuallymonitor the state of charge of each individual battery cell 1702 withinthe battery arrays 902, 904. The controller module 908 can also controlthe charge and discharge of the battery arrays 902, 904.

Disposed along a different edge of the controller module 908 is aplurality of low voltage connections 2104. The low voltage connections2104 are connected to various components within the energy storagemodule 136, such as, but not limited to, low voltage harness 910,thermistor high harness 1026 and a thermistor low harness 1028. The lowvoltage harness 910 is communicatively connected to the vehicle signalconnector assembly 814. Additional components within the energy storagemodule may also be communicatively connected to the controller module908 via high voltage harness 906, low voltage harness 910, or throughother harnesses or connections.

According to one aspect of the present disclosure, the energy storagemodules 136 within the energy storage system 134 are adapted tocommunicate with one another. In order to provide the communicativeconnection, the energy storage module data link 204 is provided betweeneach energy storage module 136. In one embodiment and generallyreferring also to FIG. 8, one energy storage module 136 functions as themaster energy storage module 802 while the others function as the slaveenergy storage modules 804. The controller module 908 within the masterenergy storage module 802 then receives information from the slaveenergy storage modules 804 and communicates with the transmission/hybridcontrol module 148 and the rest of the hybrid system as a single energystorage system 134. As discussed herein, the transmission/hybrid controlmodule 148 receives power limits, capacity available current, voltage,temperature, state of charge, status, and fan speed information from theenergy storage system 134 and the various energy storage modules 136within. The transmission/hybrid control module 148 in turn sendscommands for connecting the various energy storage modules 136 so as tosupply voltage to and from the inverter 132.

Because the controller modules 908 within the energy storage modules 136are identical, it does not matter which energy storage module is in the“master” position. According to one embodiment of the presentdisclosure, the controller modules 908 are adapted to periodicallyverify that the master energy storage module 802 is still functional. Ifnot, a slave energy storage module 804 then begins to function as themaster energy storage module and communicates with thetransmission/hybrid control module 148, thereby providing systemredundancy. According to the principles of the present disclosure, aseparate controller box or structure is not necessary and energy storagemodules 136 can be easily interchanged. Additionally, the principles ofthe present disclosure further provide an energy storage system 134 inwhich the entire system remains functional even in the event that themaster module 802 becomes inoperable. In one embodiment, the energystorage modules 136 are instructed to be a master or slave module basedupon a received address which is programmed by the jumpers withinlow-voltage signal connector 314.

Though not illustrated, controller module 908 optionally includes amemory component. The memory component may be any known memory device,such as, but not limited to, non-volatile memory, a hard disk drive,magnetic storage device, optical storage device, RAM, or ROM, just toname a few examples. Non-volatile memory is adapted to record energystorage module usage and status history, such as achieved power levelsand duty cycles, to name a few examples. The memory provides aneffective serviceability tool in which energy storage module componentperformance can be quickly obtained and evaluated. The controller 908may include additional components, such as a microprocessor capable ofperforming the various control, communication, and switching functions.

In order to stack multiple energy storage modules 136 on top of oneanother, various embodiments are contemplated. FIG. 22 illustrates onesuch embodiment. While FIG. 8 and the associated discussion primarydealt with the electrical connections between the master energy storagemodule 802 and the slave energy storage module 804, FIG. 22 concerns thephysical arrangement and connection of the two. As shown, the slaveenergy storage module 804 is stacked upon the master storage module 802.A plurality of bolts 2202 are provided through mounting holes 1024 ofboth storage modules 802, 804. The indentations 316 are located nearholes 1024 and run along the height of the energy storage modules 136 toprovide sufficient clearance for the torque wrench or other device usedto tighten the bolts 2202 during the stacking of the storage modules802, 804. With four bolts 2202 in place, the stacked arrangement isstrong enough to withstand considerable vibration and shock loads. Ascan be appreciated by those of skill in the art, more or less bolts 2202and mounting holes 1024 may be provided.

According to one aspect of the present disclosure, the energy storagemodules 136 are constructed such that they may be mounted in anyarrangement, direction, or orientation. For example, the master energystorage module 802 may be stacked upon the secondary energy storagemodule 804. In other embodiments, the energy storage modules are notstacked upon each other but are positioned in various locations withinthe HEV.

FIG. 23 depicts a frame mounting concept. An energy storage module 2302comprises a lid 2304 having a receiving element 2306 and a raisedelement 2308. The receiving element 2306 and the raised element 2308allow for additional energy storage modules 2302 to be securely stackedupon one another. The energy storage module 2302 further comprises ahousing 2310 constructed and arranged to sit upon and be mounted to themounting plate 2312. The mounting plate 2312 includes a plurality offeet 2314 which are fixed to vehicular frame 2316. In one embodiment,the energy storage module 2302 is dimensioned to fit within the areatypically reserved for a heavy duty truck fuel tank.

FIGS. 24 and 25 depict another embodiment of an energy storage module2402, similar to energy storage module 136, but with an external fanhousing 2416 and heat sink 2418. The energy storage module 2402 includesan enclosure 2404 having an upper cover 2406 which is secured to lowerhousing 2407 by screws 2408 as shown, although other methods known inthe art may be used to secure the upper cover 2406. The upper cover 2406is preferably sealed to lower housing 2407 to prevent outsidecontaminants from entering the enclosure 2404. A high voltage junctionbox 2410, similar to high voltage junction box 308, is mounted to oneend of the energy storage module 2402, along with a low voltageconnector 2412 and service disconnect 2414.

The energy storage module 2402 employs internal conduction cooling andexternal convection cooling as will be described further below. Theexternal fan housing 2416 is mounted to an opposite end 2413 of theenclosure 2404 with respect to the high voltage junction box 2410 asshown. Heat sink 2418 having fins 2419 is mounted to or formed integralto the bottom surface 2420 of the enclosure 2404. An enclosing plate2422 is mounted to enclosure 2404 as shown to further direct air acrossthe heat sink 2418. By using an external cooling fan and heat sink, theenclosure 2404 and high voltage junction box 2410 may be individually orcollectively sealed from outside contaminants. The enclosure 2404 andhigh voltage junction box 2410 may be further adapted to be submersible,depending on the needs of the particular application.

FIG. 26 depicts an arrangement wherein two energy storage modules 2402are stacked and electrically connected to provide increased operatingvoltage or current capacity as needed by the particular application.Again, bolts 2202 are included to secure the energy storage modules 2402together.

FIG. 27 depicts a bottom perspective view of the heat sink 2418arrangement. As shown, the heat sink 2418 includes a plurality of fins2419 which are disposed angularly outward with respect to thelongitudinal dimension of the energy storage module 2402. When coolingis required, the fan 2706 directs air through a central cavity 2708 inthe direction indicated by arrows 2702. The air is then directed betweenthe fins 2719 in an angularly outward direction on each side of theenergy storage module 2402. In order to provide a more uniform coolingin each battery cell, the height, length and/or relative spacing of thefins 2419 may be varied with the direction or speed of air flow. Forexample, the fins nearest the cooling fan 2706 may have a smaller heightor length than those farther from the cooling fan 2706. FIG. 28 depictsa half-symmetry reverse perspective view of the heat sink 2418 whichillustrates the varying height and length of the fins 2419.

FIG. 29 depicts another partial diagrammatic half-symmetry perspectiveview of an energy storage module housing 2902 in which a battery thermalpad 2904 is disposed for mounting a battery array thereon. The thermalpad 2904 is constructed of a thermally conductive, yet electricallyinsulating, material such as Sil-Pad®, manufactured by The BergquistCompany. The thermal pad is preferably constructed as a single piece foreach battery array to provide maximum thermal transfer. The thermal pad2904 is preferably sized to be in the range of 70-120 in², althoughsmaller and larger sizes may also be used. When a battery array ismounted on the thermal pad 2904, the thermal pad 2904 draws heat awayfrom the battery array and into the heat sink 2418 by thermalconduction. As discussed above, the excess heat is then removed from theheat sink 2418 by convection due to the movement of air across the fins2419.

FIG. 30 provides a more detailed view of one end of the energy storagemodule 2402 including the high voltage junction box 3010, similar tohigh voltage junction box 308. As shown, the front perimeter 3022 of thehigh voltage junction box 3010 is sealed and protected by an accesscover 3012. The rear of the high voltage junction box 3010 is preferablyopen to a corresponding opening 3604 in the lower housing 2407 (see FIG.36). The rear perimeter 3020 of the high voltage junction box 3010 mayalso be sealed about the opening 3604 of lower housing 2407 to allow thehigh voltage junction box 3010 and enclosure 2404 to collectively sealout foreign contaminants and/or be made submersible. High voltageconductors 3014 and 3016 are connected within the high voltage junctionbox 3010 and also preferably sealed to prevent entry of foreigncontaminants. Strain reliefs 3018 and 3024 may be included to furthersecure the high voltage conductors 3014, 3016.

FIG. 31 depicts the high voltage junction box 3010 with the access cover3012 removed. For precautionary purposes, a safety cover 3110 isprovided to act as a further barrier to the high voltage terminalsbehind it, similar to safety cover 706 of FIG. 7B. In order to accessthe high voltage connections behind the safety cover 3110, a highvoltage interlock (HVIL) resistor 3114 must first be removed.

FIG. 32 depicts the high voltage junction box 3010 with the safety cover3112 and HVIL resistor 3114 removed. In the illustrated embodiment, aplug-in bussed electrical center (BEC) 3210 is located within the highvoltage junction box 3010, and external to the enclosure 2404. Bylocating the BEC 3210 outside the enclosure 2404, the upper cover 2406does not need to be removed when the energy storage module 2402 is beingserviced. This decreases the safety risk to the technician and furtherprevents contaminants from unnecessarily reaching the components locatedwithin the enclosure 2404.

As shown in FIGS. 33A and 33B, the plug-in BEC 3210 offer a furtheradvantage in that it requires less manual connections during assembly orservice, further decreasing the safety risk to the technician. Morespecifically, the high voltage connections between the plug-in BEC 3210and the live battery arrays are made using bus bar blade terminals 3316and 3318, which mate to corresponding receiving terminals in the highvoltage junction box 3010 as the BEC 3210 is installed. Then, theterminals 3312 and 3314 which connect the plug-in BEC 3210 to thevehicle power systems may be connected. In other words, the operatordoes not have to manipulate flexible cables which might be connected tothe live battery arrays when installing or removing the BEC 3210 forservice. The plug-in BEC may also include a current sensor 3320, currentsensor connector 3321, fuse block 3222, high voltage sense connector3324, low voltage connector 3326, and high voltage contactors 3328.

FIG. 34 shows an exploded perspective view of the energy storage module2402 with the upper cover 2406 removed. As shown, an energy storagecontroller module 3410, similar to energy storage +controller module 908of FIG. 9, is mounted within the enclosure 2404 in an alternatearrangement. FIG. 35 shows a reverse perspective view of the energystorage module 2402 with the upper cover 2406 and fan housing 2416 alsoremoved. As shown, the energy storage module 2402 includes two batteryarrays 3510 and 3512, which are similar in function to the batteryarrays 902 and 904 of FIG. 9.

FIG. 36 shows an exploded view of the fan housing 2416. Because theenergy storage module 2402 is implemented as a sealed or submersibleunit, any battery gases which might escape from the battery cells withinbattery arrays 3510 and 3512 will be trapped within the enclosure 2404.The resulting increased pressure may damage the enclosure 2404 andassociated seals. A pressure relief panel 3610 is therefore provided toallow the battery gases to escape if the pressure reaches apredetermined threshold. As shown in further detail in FIG. 37, thepressure relief panel 3610 includes a compliant seal 3710 which seals avent opening 3616 in the enclosure 2404. The pressure relief panel 3610and seal 3710 are held against the vent opening by bracket 3614 inconjunction with springs 3612. The bracket 3614 is secured to theenclosure 2404 with fasteners, such as screws 3617. Springs 3612 areheld between the bracket 3614 and pressure relief panel 3610 and holdthe pressure relief panel 3610 in place. The springs 3612 may belaterally secured by protrusions 3712 in the pressure relief panel andcorresponding protrusions 3615 in the bracket 3614. The protrusions 3712and 3615 extend into the interior of springs 3612 when the unit isassembled. The springs are selected to allow the pressure relief panel3610 to temporarily move outward from the lower housing 2407 at theselected threshold pressure, compressing the springs and relieving thepressure inside the enclosure 2404. Once the pressure is relieved, thesprings force the pressure relief panel 3610 back against the lowerhousing 2407, resealing the enclosure 2404.

FIG. 38 shows an exploded view of one of the battery arrays 3510, 3512.As shown, the battery array 3510 includes a plurality of battery cells3810 separated from one another by cell retainers 3812, in a similarfashion to the battery cells 1702 of FIG. 17. The cell retainers 3812may be formed from an insulative material, such as plastic or othersuitable dielectric, and are of sufficient thickness to limit heattransfer between individual battery cells 3810 to an acceptable level.In the case where a cell 3810 develops an internal short and heats upbefore venting, the insulative property of the cell retainer 3812 willreduce the amount of heat that propagates to adjacent cells 3810. Thisallows the heat in the shorted cell to escape through other coolingpaths, preventing nearby cells from heating up and venting themselves.Again, the battery cells 3810 are secondary batteries capable of beingrepeatedly charged and discharged, such as, but not limited to, nicad(Ni—Cd), nickel-hydride, and/or lithium-ion types. Battery cellsmanufactured by Samsung, Sanyo and GS Yuasa Corporation have been foundto be acceptable depending upon design and size considerations.

At each end of the battery array 3510 is an end plate 3814, which worksin conjunction with two side rails 3816 to hold the battery cells 3810and the cell retainers 3812 in place. An insulation liner 3815 may alsobe included which improves creepage and clearance of the battery cells3810 when assembled. Compression limiters 3826 may also be provided toprovide additional strength when the side rails 3816 are implemented astrusses, as shown in FIG. 38. Once the battery cells 3810, cellretainers 3812, end plates 3814, and side rails 3816 are properlyaligned, the structure is held together by pins 3818 and nuts 3819. Thepins 3818 are inserted through holes 3820, 3822 in the side rails 3816and insulation liners 3815, respectively. The end plates 3814 includeflanges 3823 which secure the end plates 3814 behind the pins 3820. Thepin arrangement provides more secure holding and helps prevent torqueloosening during operation. In one embodiment, the battery array 1700 ismade up of forty six individual battery cells 1702.

Voltage sense board assembly 3830 is installed above the battery cells,followed by safety covers 3032. The safety covers 3032 are constructedfrom plastic or other appropriate electrically insulating material. Thevoltage sense board assembly 3830 includes a harness connection 3834which is constructed and arranged to connect to the controller module3410 and/or plug-in BEC 3210. FIG. 39 shows a perspective view of theassembled battery array 3510.

FIG. 40 illustrates an end view of a battery cell 3810 mounted withinthe battery array 3510. Bus bars 4010 provide an electrical connectionbetween the voltage sense board assembly 3830 and the cell terminals4012, connecting the positive terminal of one battery cell to a negativeterminal of an adjacent battery cell. This results in a serieselectrical connection between the battery cells 3810, collectivelyproviding the desired total array voltage. Thermistor 4020 may beincluded to monitor the temperature of the battery cell 3810 andcommunicate the temperature reading to controller module 3410.

In certain embodiments, the voltage sense board assembly 3830 isinitially provided with certain bus bars 4010 missing as shown by arrows4114 in FIG. 41. Due to the missing bus bars, the voltage sense board3830 is electrically divided into voltage sections 4112 until near theend of the assembly process. The covers 3032 include the missing orfinal bus bars (indicated as 4116 in FIG. 38) which complete the missingconnections as each individual cover 3032 is installed in sequence. Thecovers 3032 include an insulated overlap portion 4118 which covers thefinal bus bar 4116 of the adjacent cover 3032. The result is that thetechnician is only exposed to a limited safe voltage level (e.g., lessthan 50 volts) from the exposed battery cell terminals until the finalconnections are made.

FIG. 42 depicts a frame mounting concept according to another embodimentof the disclosure. As shown, the enclosure 2404 of energy storage module2402 is mounted to vehicular frame 4208 using isolator mounts 4210. Theisolator mounts are constructed of a compliant material, such as rubberor silicone, and reduce the vibration transferred from vehicular frame4208 to the energy storage module 2402. One example of a suitableisolator mount is the Barry Controls 200 series Cup Mount Isolator. Anadapter bracket 4310 may be provided as shown in FIG. 43 to evenlydistribute the weight of the energy storage module 2402 across thesupport surface 4312 of the isolator mount 4210 and allow connection tothe energy storage module 2402 using a single fastener 4314.

FIGS. 44 and 45 illustrate a detailed view of a mounting arrangement forthe thermistor 4020 according to one embodiment. The thermistor 4020needs to maintain mechanical contact with the battery cell 3810 toprovide accurate monitoring. However, the battery cells 3810 may vary inheight due to manufacturing variations, resulting in a correspondingvariation in the distance between the voltage sense board 3830 (in whichthe thermistor is mounted) and the top surface 4410 of the battery cell3810. To account for this variation in distance, the thermistor 4020 maybe installed within a flexible clip 4412 as shown. The flexible clip4412 includes lateral portions 4414 which may flex vertically to holdthe thermistor tip 4416 against the top surface 4410 of battery cell3810. The clip 4412 further includes vertical portions 4418 which aresecured in holes 4420 by tabs 4422. The thermistor 4020 may be securedto the clip 4412 using a potting material 4424 as shown. Other types ofmaterials may also be used to fix the thermistor within the clip 4412,such as adhesives, cement, or the like. To provide further adjustabilityand tolerance, the thermistor tip 4416 may be encased in a compliantmaterial 4426 which provides mechanical flexibility and thermaltransfer, such as a thermoplastic elastomer (TPE). The compliantmaterial 4426 and the clip 4412 work in combination to retain the tip ofthermistor 4020 against the top surface 4410 of the battery cell 3810.

As can be appreciated by those of skill in the art, a single energystorage module 136 may be used or a plurality of energy storage modules136 can be connected to one another in a series, parallel, orseries/parallel fashion. In one embodiment, multiple energy storagemodules 136 may be connected in parallel to provide a 300V system, whiletwo or more pairs of energy storage modules may be connected in seriesor series/parallel to provide a 600V system. Because the energy storagemodules 136 can easily be incorporated into a 300V or 600V HEVapplication, the electronics are designed to meet the specifications ofthe higher voltage systems, such as creepage and clearance issues.Accordingly, arcing is of no concern when the energy storage module isused in a 600V setting. FIG. 46A shows an embodiment where a singleenergy storage module 136 is used. FIG. 46B shows an embodiment wheretwo energy storage modules 136 are connected in parallel. FIG. 46C showsan embodiment where two energy storage modules are connected in series.FIG. 46D shows an embodiment where two pairs of energy storage modules136 are connected in a series/parallel arrangement. It shall beunderstood that energy storage module 2402 may also be connected invarious series, parallel, or series/parallel arrangements as discussedwith respect to energy storage modules 136.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges, equivalents, and modifications that come within the spirit ofthe inventions defined by following claims are desired to be protected.All publications, patents, and patent applications cited in thisspecification are herein incorporated by reference as if each individualpublication, patent, or patent application were specifically andindividually indicated to be incorporated by reference and set forth inits entirety herein.

1. An energy storage system, comprising: at least one energy storagemodule adapted to supply electrical energy to a hybrid vehicle, theenergy storage module comprising: a primary enclosure; at least onebattery array located within the primary enclosure, the battery arrayhaving a plurality of battery cells, and; a pressure relief paneldisposed within the primary enclosure, the pressure relief paneloperable to limit internal pressure of the primary enclosure.
 2. Theenergy storage system of claim 1, wherein the pressure relief panelcomprises: a compliant seal; and at least one spring to maintain thecompliant seal about a vent opening in the primary enclosure.
 3. Theenergy storage system of claim 2, wherein the pressure relief panelcomprises a plurality of protrusions to laterally secure the at leastone spring.
 4. The energy storage system of claim 3, wherein theprotrusions are disposed to extend into an interior cavity of the atleast one spring.
 5. The energy storage system of claim 2, wherein thepressure relief panel and compliant seal are held against the ventopening by a bracket in conjunction with the at least one spring, thebracket being coupled to the primary enclosure with the spring beingdisposed between the bracket and the pressure relief panel.
 6. Theenergy storage system of claim 5, wherein the bracket comprises aplurality of bracket protrusions to laterally secure the at least onespring.
 7. The energy storage system of claim 6, wherein the bracketprotrusions are disposed to extend into an interior cavity of the atleast one spring.
 8. A pressure relief panel assembly for a hybridvehicle energy storage system, comprising: a pressure relief panelhaving a compliant seal, and; at least one spring; wherein the at leastone spring maintains the compliant seal about a vent opening in a energystorage module adapted to supply electrical energy to a hybrid vehicle.9. The pressure relief panel assembly of claim 8, wherein the pressurerelief panel comprises a plurality of protrusions to laterally securethe at least one spring.
 10. The pressure relief panel assembly of claim9, wherein the protrusions are disposed to extend into an interiorcavity of the at least one spring.
 11. The pressure relief panelassembly of claim 8, wherein the pressure relief panel and compliantseal are held against the vent opening by a bracket in conjunction withthe at least one spring, the bracket being coupled to the energy storagemodule with the spring being disposed between the bracket and thepressure relief panel.
 12. The pressure relief panel assembly of claim11, wherein the bracket comprises a plurality of bracket protrusions tolaterally secure the at least one spring.
 13. The pressure relief panelassembly of claim 12, wherein the bracket protrusions are disposed toextend into an interior cavity of the at least one spring.